Directional dispensing grenade with externally open,integrally formed and internally closed,propellant-charge well



May), 1970 1. R. BARR 3,512,480

DIRECTIONAL DISPENSING GRENADE WITH EXTERNALLY OPEN. INTEGRALLY FORMED AND INTERNALLY CLOSED, PROPELLANT-CHARGE WELL Original Filed March 31, 1966 IRWIN R. BARR lNVENTOR ATTORNEY United States Patent 3 512 480 DIRECTIONAL nlsrufizsnsto GRENADE WITH EX- TERNALLY OPEN, INTEGRALLY FORMED AND INTERNALLY CLOSED, PROPELLANT-CHARGE WELL Irwin R. Barr, Lutherville, Md., assignor to AAI Corporation Cockeysville, Md., a corporation of Maryland Continuation of application Ser. No. 539,101, Mar. 31, 1966. Thisjapplication Dec. 4, 1967, Ser. No. 699,277

' Int. Cl. F42b 27/00 ITS.C]. 102--64 7 Claims ABSTRACT OF THE DISCLOSURE A directional dispensing grenade is disclosed having a canister, a portion of which has a substantially constant cross-sectional bore area with an obturating piston disposed therein that is adapted to be propelled through the canister. The open bore end of the canister is closed with. a cap extending across the open bore end and a frusto-conical surface slopes inwardly from the bore wall to a blow-out disc formed integrally with the end closure cap. Between the piston and the end cap is a charge of powder material to, be dispensed which, when the piston exerts a force against it, causes the disc to be blown out and is expelled through the resulting blow-out orifice in the end cap. -In the opposite end of the canister is an integrally formed, internally protruding and internally closed but externallyopen propellant-charge well with a rupturable bottom. The well contains an ignitable propellant-gas-generating charge which is effectively sealed therein by a cap inserted into the well which has a percussion primer and a fuze disposed therein that are adapted to ignite the propellant-gas-generating charge to produce a propellant gas which will rupture the bottom of the well and propel the piston through the canister. The striking surface of the percussion primer is externally, exposed and adapted to be struck by the firing pin of a resiliently biased hammer which is mounted between two parallel ribs and is normally prevented from striking the percussion primer by a handle and a safety pin which releasably retain the hammer in a resiliently biased, cocked position.

.This application is a continuation of application Ser. No. 539,101, filed Mar. 31, 1966, and now abandoned.

This invention relates to an improved grenade dispenser which is particularly adapted to selective direc tional discharge or dispensing of material through the ignition of a gas-generating charge in the dispenser.

Grenades and dispensers have been made heretofore employing various constructions. Among the problems associated withjgrenade dispensers for sensitive or chemically reactive materials are the sealing of the propellant charge material from the material to be dispensed, and also providing for safety of loading of the entire grenade dispenser with both the dispensed material charge and the propellant mixture charge. Another problem lies in the provision of a simple and inexpensive grenade dispenser which will permit relatively quick and effective discharge of material therefrom without contamination of the discharged material by the propellant gases generated by a propellant charge.

It isa major object and feature of this invention to provide a grenade dispenser employing a propellant charge and a charge. of material for dispensing or discharging, in. which the material to be dispensed, hereinafter termed discharge material, is hermetically sealed from the propellant charge and from the atice mosphere while in stored condition, and which is substantially effectively sealed from the gases generated by the propellant charge during firing of the charge and propelling of the discharge material from the grenade.

A further feature of the invention lies in the provision of a grenade dispenser of simple design which enables preloading and hermetic sealing of discharge material and an operation pusher piston within a main body canister, the main body being provided with an externally open well into which the propellant charge and actuating assembly therefor may be thereafter inserted and secured, thereby enabling safe and effective loading of the grenade without contamination of the discharge material, and removing propellant explosive dangers to the loading operator during loading of the discharge material while minimizing the hazards of subsequent loading of the propellant charge and associated actuating assembly.

Still other objects, features and attendant advantages will become apparent to those skilled in the art from a reading of the following detailed description of one physical embodiment constructed in accordance with the invention, taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a longitudinal section of a grenade dispenser constructed according to the invention;

FIG. 2 is an end View of the arrangement of FIG. 1, as viewed toward the propellant-charge-containing end of the dispenser; and

FIG. 3 is an end view of the opposite dispensing end of the dispenser.

Referring now to the figures of the drawings, the illustrative grenade dispenser generally indicated at 11 includes a canister body 13 having formed unitarily therewith a closed end wall 13a in which is formed a well 23 having a unitary rupturable membrane wall portion 23:: formed across the bottom thereof. The canister also includes an opposite end wall formed by a plug or cover 15 which is suitably hermetically sealed to the adjacent side wall portion of the man body as along the lines 17, 19, as through spin welding, or by suitable adhesive or bonding agents.

Prior to assembling and securing the end 15, a piston pusher 21 is inserted in the canister body 13 through the open end of the body, and a charge of discharge material M to be dispensed is placed in the body 13 also through the open end thereof. The discharge material M is preferably in comminuted form, such as powder or particle size, and is generally flowable, although the apparatus may conceivably also be employed for dispensing liquids or liquid and particle mixtures. The dispenser 11 is particularly suited for dispensing tear gas-forming particles or powders, especially in view of the ability to maintain segregation between the powder charge M and the propellant charge, as will be hereinafter apparent.

The piston 21 is substantially complementary to the substantially constant diameter longitudinally extending inner wall of the chamber or compartment within the body 13 in which the particle charge M is carried. Preferably, the piston pusher 21 has a tapered edged annular obturating flange which is slightly oversized along its feathered edge zone, as of the order of several thousandths of an inch, and which engages the internal wall of the canister body in a light press fit. This light press fit aids in initial sealing between the particle charge M and the propellant gases upon firing of the propellant charge, as subsequently described, and the obturating flange aids in continued sealing of the particle charge M from the propellant gases during movement of the piston pusher 21 toward the discharge end of the canister 13.

The end cap or cover 15 has an internal forwardly and inwardly sloping tapered end wall terminating in a blowout disc 15a which is recessed from the external end wall of the cover 15 to reduce the hazard of inadvertent rupture from outside forces. An annular shear relief groove 15b is formed around the blowout disc 15a to aid in the desired full shear rupture and blowout of the entire disc 15a upon movement of the piston pusher 21 theretoward and compression of the material M to a point at which the internal pressure overcomes the shear strength of the annular web formed at the shear relief groove 15b.

After insertion of the piston pusher 21 and particle material M and hermetic sealing of the end cover 15 to the main body of the canister 13, the propellant charge and actuating assembly may then be added to the canister body at the opposite end 13a. To this end, a propellant charge of suitable gas-generating powder 27 may be poured or added directly into the bottom of the well 23, although a further container with a blowout bottom may also be used to hold the powder charge 27 within the bottom-closed well if desired. End cap 25 is secured in the well through the medium of a pair of retainer pins 35 disposed in respective bores formed in an extension of the well wall, and in a complementary side groove of the cap 25. As an aid in pressure retention after ignition of the propellant charge 27, an annular O-ring 26 may be disposed in an annular groove on the cap 25. The end cap 25 houses a percussion primer 29, the striking surface of which is disposed adjacent the outer surface of the end cap, and this primer may be retained in place generally by a press fit and against axial outward movement as by an annular lip 25b. A pyrotechnic time delay fuze 31, such as a suitable mix of relatively slow and high temperature lburning power grains, is preferably disposed between the primer 29 and the propellant-gasgenerating mix 27. If a time delay is not desired or required, the powder charge may be in direct connection 'with the primer 29, or a high temperature burning flash charge may be disposed in this zone which is occupied by the timer mix 31 to aid in ignition of the gas-generating mix 27. To insure against burning of the plastic end cap during ignition of the fuze 31, with consequent blowby of gas pressure past the primer 29, a metallic sleeve 33 is preferably disposed about the fuze 31 and the zone between the primer and the propellant-gas-generating mix 27.

The end 13a of the canister body 13 has two parallel ribs 13b formed thereon, which serve the dual function of reinforcement of the end wall 13a and also as a mount for a percussion hamper 37 and firing pin 37a for the percussion primer 29. The hammer 37 is secured to the end wall ribs 13b through the medium of a pin 38 which is press fit into undersized aligned bores formed in the ribs 13b. A suitable torsion coil spring 40- may be mounted on the pin 38 and serves to provide the necessary force for actuation of the hammer and firing pin assembly 37, 37a, into percussion engagement with the primer 29. In the ready position as shown in FIG. 1 the hammer 37 is retained between the protruding ribs 13b by a generally L-shaped handle 41, which is releasably locked in position by a reverse bend end lip 41a engaged with an annular lip flange 25a formed on the end cap 25, and by a pull ring and pin unit 39, 39a which extend through aligned apertures in the ribs 13b and side ears formed on the handle 41.

It Will be appreciated that this grenade dispenser arrangement lends itself particularly well to the utilization of plastic material, such as especially Delrin acetal resin in view of its strength, structural stability, and high resistance to chemical attack, for the major parts, including particularly the canister, piston, and primer-timer-propellant charge enclosure. This permits relatively inexpensive manufacture and aids materially in increasing the usefulness of the apparatus for dispensing various chemically active materials, especially when long term storage before dispensing is found necessary.

The grenade dispenser may be operated either as a hand-held dispenser, with the discharge end 15 pointed away from the body, or the entire unit 11 may be thrown or projected after pulling the pull ring and retainer pin 39, 39a from the canister. Upon pulling the pin 39, the hammer 37 will, after physical release of the handle 41, move under the influence of spring 40 to cause the handle 41 to be moved away from the canister 13, and the hammer 37 will carry the firing pin 37a into percussion engagement with the primer 29 to thereby ignite the time delay fuze 31, or in the event that a time delay is not desired the propellant gas generating mix will be substantially immediately ignited. Upon ignition of the propellant gas mix 27 the thin membrane 23a will be ruptured by the expansion of the burning mix 27 and resultant gas pressure build-up. Due to the relatively large volume of the compartment formed about the well 23 between the piston 21 and the end wall 13a of the canister as compared to the propellant chamber size, it will be seen that the normal tendency for a short duration high peak pressure on the piston 21 shortly after ignition of the mix 27 will be substantially reduced, and the energy will thereby be more evenly distributed in pressure throughout the stroke of the piston. The piston pusher 21 will be moved toward the discharge end wall 15 under the influence of the gas pressure generated by the mix 27, and the resultant increase in pressure in the particle charge M will effect rupture of the annular shear membrane surrounding the blowout disc 15a, whereupon the particle material M will be discharged through the resulting fully open orifice along the general direction in which the grenade canister body 13 is pointed. The tapered end wall 150 of the cover 15 aids in the movement of the particle material M toward and through the discharge opening, thereby reducing any tendency of the material to pack and remain along the side wall zone of the container. The rate of discharge of the material M from the grenade 11 is dependent upon the overall viscosity of the particulate material M and the burning and gas generating rate as well as the total quantity of the propellant-gas-generating mixture 27. Inasmuch as in most all instances the movement of the piston pusher 21 will be relatively rapid, the particulate or other material M will be substantially entirely discharged from the canister 13 Without necessity for the piston 21 to exactly conform to the tapered end wall 15c, although such may be so formed, particularly when relatively slow rates of movement of the piston 21 are to be utilized or when relatively high viscosity material is being dispensed.

That which is claimed is:

1. A directional dispensing grenade comprising:

a hermetically sealed canister having a section of body material forming a blowout opening for discharge of material therethrough,

said canister having an internal cavity therein, for

carrying a charge of particulate material for directional discharge into the atmosphere,

said canister having an internally protruding and externally open well, extending reversely into said cavity, with an integral closed bottom wall and annular side wall, formed integrally in and by a unitary end wall thereof opposite the end wall having said blowout opening section,

a 'wall of the integral vsaid well forming a rupturablc membrane,

a propellant-gas-generating charge in closed secured relation within said well,

enclosing means enclosing and sealing said propellantgas-generating charge within said well, and

a percussive ignition unit at said well and in ignition-chain-initiation relation to said propellant-gasgenerating charge, and being disposed for external percussive ignition of said unit, and percussive striking means carried externally of said canister for percussive ignition of said percussive ignition unit, for igniting said propellant-gas-generating charge to thereby rupture said hermetically sealed canister at said well blowout membrane, and effect movement of said charge of particulate material toward and through said discharge blowout opening.

2. A directional dispensing grenade according to claim 1,.

said cavity being of substantially constant cross-sectional size and shape along a major portion of its length for accommodation of movement of a piston therealong, and

a piston disposed within said cavity and spaced longitudinally from said blowout opening section and forming one wall of a compartment, the remainden of which compartment is bounded by the con 'stantsized wall portion of said cavity and a transverse end wall including said blowout opening section for containing said charge of flowable material to be discharged through said opening.

3. A directional dispensing grenade according to claim 1, said percussive ignition unit being mounted in said well adjacent and effectively communicable with said propellant-gas-generating charge.

4. A directional dispensing grenade according to claim 3, 1

said unitary opposite end wall having two spaced parallel external ribs formed thereon,

said percussive igniting unit comprising a percussion primer,

a spring-biased percussion hammer mounted on and between said ribs adjacent said primer for percussion ignition of said primer,

an L-shaped handle extending across said well, said primer and said hammer, and along the external side wall surface of said canister, and

a releasable pin extending through said ribs and anchoring said handle in pre-fire safety position.

5. A directional dispensing grenade according to claim 4, said well having an end cap secured therein in which is mounted said percussion primer, and an opening formed in said cap for communication between said primer and said propellant-gas-generating charge.

6. A directional dispensing grenade according to claim 5, further comprising a time delay fuze disposed between said primer and said propellant-gas-generating charge, said cap being formed of plastic material susceptible to high temperature erosion and damage, and a metallic sleeve surrounding said delay fuze between said primer and said propellant-gas-generating charge.

7. A directional dispensing grenade according to claim 1,

said piston having an annular pressure-sealing obturat ing flange on the face thereof opposite said compartment,

said obturating flange being tapered-edged and slightly oversized and forming a light press fit with the adjoining said cavity wall,

said cavity and piston forming a second open compartment surrounding said well, and

said second compartment serving as an initial pressure-damping compartment for reducing peak effective pressure on said piston after ignition of the propellant-gas-generating charge.

References Cited UNITED STATES PATENTS 1,276,434 8/ 1918 Steinmetz 102-64 2,437,001 3/1948 Petersen 102-64 2,925,942 2/1960 Schmidt et a1. 222-389 3,207,385 9/1965 Featherstone et al. 222-389 3,343,699 9/1967 Nicko 222-541 3,380,383 4/1968 Schnepfe 102-64 VERLIN R. PENDEGRASS, Primary Examiner 

